The epidemiology of HIV in the Asia-Pacific region reflects local drivers of infection (e.g., male-to-male sex, injection drug use), key co-infections that impact treatment outcomes (e.g., hepatitis B and 0, tuberculosis), and a range of treatment access and national resource levels. In addition, emerging evidence suggests that the pharmacology and toxicity of antiretroviral drugs in Asian populations are significantly different from Caucasian patients, which could impact long-term treatment tolerability and success. The overall goal of the Asia-Pacific HIV Research Collaboration is to evaluate the impact of HIV disease, co-infections, and ART management on clinical outcomes in the region. Research builds on existing scientific capacity for both broad regional and multiregional analyses and targeted studies on specific outcomes of interest within at-risk populations. The core research relies upon data from the Asia-Pacific HIV Observational Database (APHOD), comprised of the TREAT Asia HIV Observational Database (TAHOD) and the Australian HIV Observational Database (AHOD). Core research also includes the TREAT Asia Pediatric HIV Observational Database (TApHOD). These three established cohorts include data from 60 clinical centers at 54 institutions in 14 South, Southeast and East Asian countries and Australia. A separate collaboration with the National Center for AIDS/STD Control and Prevention (NCAIDS), China CDC, will conduct epidemiologic studies using the China National ART Database, a national surveillance program. Data collection will expand current studies in several innovative areas, with specific aims looking at factors driving the epidemic, as well as the response to ART, impact of co-infections, toxicity of first- and second-line regimens, cancer risk, chronic AIDS- and non-AIDS-related events and outcomes, drug resistance patterns, and cultural and behavioral factors affecting patient management and outcomes. The inclusion of research sites from a wide variety of geographic and socio-economic settings will continue to strengthen the existing adult and pediatric research networks. Successful implementation of these studies will build up an evidence base to inform HIV clinical management practices and programs, advise national and regional treatment guidelines, and add to global understanding of the epidemiology of HIV. RELEVANCE: Published findings on short- and long-term HIV treatment outcomes will lead to more effective, evidence- based clinical management practices for HIV-infected adults and children in the Asia-Pacific region. Identifying risk factors for cancer will help guide future prevention and screening efforts. Participating sites will gain capacity to expand local and regional research activities to better understand the epidemiology of HIV.